Submission doc.: IEEE 11-13/0523r2 May 2013 Katsuo Yunoki, KDDI R&D LaboratoriesSlide 1...
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Submission doc.: IEEE 11-13/0523r2 May 2013 Katsuo Yunoki, KDDI R&D Laboratories Slide 1 Understanding Current Situation of Public Wi-Fi Usage - Possible Requirements for HEW - Date: 2013-05-12 N am e A ffiliations A ddress Phone em ail K atsuo Y unoki KDDIR&D Laboratories 3-10-10 Iidabashi, Chiyoda, Tokyo 102-8460, Japan [email protected] Y asunao M isawa KDDIR&D Laboratories Authors:
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Transcript of Submission doc.: IEEE 11-13/0523r2 May 2013 Katsuo Yunoki, KDDI R&D LaboratoriesSlide 1...
Submission
doc.: IEEE 11-13/0523r2May 2013
Katsuo Yunoki, KDDI R&D LaboratoriesSlide 1
Understanding Current Situationof Public Wi-Fi Usage
- Possible Requirements for HEW -
Date: 2013-05-12
Name Affiliations Address Phone email Katsuo Yunoki KDDI R&D
Laboratories 3-10-10 Iidabashi, Chiyoda, Tokyo 102-8460, Japan
Yasunao Misawa KDDI R&D Laboratories
Authors:
Submission
doc.: IEEE 11-13/0523r2May 2013
Katsuo Yunoki, KDDI R&D LaboratoriesSlide 2
Introduction
• Problem StatingSo many public Wi-Fi spots have been deployed in Japan. However, they have not been used so much as we expected. Why??
• Understanding Current SituationThroughput measurement and frame monitoring were executed at a train station as an example of current public Wi-Fi usage.
• Proposing Possible RequirementsPossible requirements are proposed from observed results.
Submission
doc.: IEEE 11-13/0523r2May 2013
Katsuo Yunoki, KDDI R&D LaboratoriesSlide 3
Problem Stating
- KDDI has deployed over 200,000 APs in public areas nationwide. (As of Sep. 2012)
- However, the public Wi-Fi service has not been used so much from mobile devices as we expected.
- The reasons include customers’ unsatisfaction with its data throughput at some places or sometimes.
It makes customers to switch Wi-Fi function off on their Smartphones.
KDDI has taken many actions to make Wi-Fi use easier and more convenient. Refer to backup slides about them.
Submission
doc.: IEEE 11-13/0523r2May 2013
Katsuo Yunoki, KDDI R&D LaboratoriesSlide 4
Understanding Current Situation(Real Example)
Throughput measurement and frame monitoring were executed: - At Shibuya station of Tokyo Metro (under ground)- During 19:00-20:00 on April 15 (MON), 2013
Submission
doc.: IEEE 11-13/0523r2May 2013
Katsuo Yunoki, KDDI R&D LaboratoriesSlide 5
Real Example (1)Download throughput
Thro
ughpu
t (M
bps)
Wi-Fi (2.4GHz) is slower than LTE.
Why is 2.4GHz slower??
Measured by Android 4.1 device.
Submission
doc.: IEEE 11-13/0523r2May 2013
Katsuo Yunoki, KDDI R&D LaboratoriesSlide 6
Real Example (2)Channel usages
2.4GHzCH1 5GHz higher bandCH12
0
By Wifi Analyzer (Android App.)
5GHz lower band
No APs existed.
Frames monitored on CH1 and Ch120 (Slide 7)
Submission
doc.: IEEE 11-13/0523r2
Katsuo Yunoki, KDDI R&D Laboratories
Real Example (2)Number of APs and STAs
Number of APs and STAs was counted from “Source Addresses” in MAC header of observed frames.Number of APs was assumed from observed source addresses of Beacon frames.
Slide 7
May 2013
<CH1> <CH120>
min. 1 2 3 4 5 Ave.
STA119
0138
7159
7181
5129
3145
6
AP 140 134 141 150 137 140
min. 1 2 3 4 5 Ave.
STA 745 579 482 548 458 562
AP 16 7 7 9 8 9
(min) (min)
Submission
doc.: IEEE 11-13/0523r2
Katsuo Yunoki, KDDI R&D Laboratories
Real Example (3)Channel Utilization
“Channel Utilization” contained in “BSS Load IE” of Beacon/Probe Response frames with a specific BSSID.
Slide 8
May 2013
<CH1> <CH120>
0 5 min 0 5 min
Submission
doc.: IEEE 11-13/0523r2May 2013
Katsuo Yunoki, KDDI R&D LaboratoriesSlide 9
Real Example (4)Frame type profile
(Fra
mes
)
Frame type CH1 CH120
Unrecognized
2143 (2%) 510 (1%)
ACK 14996 (12%) 6720 (13%)
Data 19790 (16%) 10754 (21%)
Control 7522 (6%) 5178 (10%)
Management
79144 (64%) 28587 (55%)
Total 123595 (100%)
51749 (100%)
Retry frames
34.4% 21.8%
CH utilization
80~90% 5%
No. of fames per CH
During 5 minutes.Frame capturing and throughput measurement weren’t executed simultaneously.
Submission
doc.: IEEE 11-13/0523r2
Katsuo Yunoki, KDDI R&D Laboratories
Real Example (4)Breakdown of Management
frames
Slide 10
May 2013(F
ram
es
)
Frame type Qtty. %
Others 1,314 2%
P. Response 44,355 56%
P. Request 7,698 10%
Beacon 25,878 33%
Frame type Qtty. %
Others 527 2%
P. Response 6,298 22%
P. Request 1,776 6%
Beacon 19,966 70%
<CH1>
<CH120>
On CH1, the majority is Probe Response.
Submission
doc.: IEEE 11-13/0523r2May 2013
Katsuo Yunoki, KDDI R&D LaboratoriesSlide 11
Observed results
Comparing with 5GHz band, 2.4GHz band has:(1)Lower throughput(2)More APs/STAs existing on the same
channel(3)Higher channel utilization(4)Lower channel use efficiency(5)More Management frames
11ai will reduce frames for AP discovery and link setup.
(6)More retry frames
Submission
doc.: IEEE 11-13/0523r2May 2013
Katsuo Yunoki, KDDI R&D LaboratoriesSlide 12
Considerations
- In the market, the number of devices supporting 2.4GHz only is still larger than that of devices supporting 5GHz.One of the reasons of lower throughput is large number
of devices existing.5GHz band will also be congested in the future as 5GHz
supported devices become more popular.- More frame conflicts and losses happen in 2.4GHz
band because of channel overlapping with neighboring channels.Even in 5GHz band, existence of hidden terminals may
cause frame conflicts and losses. Some of the solutions for HEW will be derived from solutions for mitigating issues of 2.4GHz band.
Submission
doc.: IEEE 11-13/0523r2May 2013
Katsuo Yunoki, KDDI R&D LaboratoriesSlide 13
Possible requirements for HEW
- The following requirements are proposed for HEW:Enhanced access control for assuring
tolerable bandwidthMitigation method for frame conflicts and
losses They might require not only PHY layer
improvement but MAC layer improvement.
- We hope that the new standard maximize performance and value of Wi-Fi by including requirements.
Submission
doc.: IEEE 11-13/0523r2May 2013
Katsuo Yunoki, KDDI R&D LaboratoriesSlide 14
Backup SlidesActions for making Wi-Fi use easier and more convenient taken by KDDI are introduced as following slides about:
1. APs rolled out with 5GHz channels support2. High Wi-Fi usage at home3. Connection Manager App.4. Connect/Disconnect control5. EAP authentication6. R&D activity
Submission
doc.: IEEE 11-13/0523r2
Katsuo Yunoki, KDDI R&D LaboratoriesSlide 15
May 2013
- Public Wi-Fi AP for KDDI Smartphone Users
200,000 spotsAs of Sep. 2012
- IEEE802.16e-based Mobile WiMAX
- 94% POPS as of Nov. 2012- Operated by UQ
communications
- CATV & FTTH bundle service
- Smart TV Box Android-based STB
Stimulating Fixed-NW usage
Home AP
- Indoor Wi-Fi router at Home for KDDI Smartphone Users.
- More than 1.2M installed. (As of Sep. 2012)
Public Wi-Fi spot
KDDI's approaches for growing wireless data demand
Submission
doc.: IEEE 11-13/0523r2
Katsuo Yunoki, KDDI R&D Laboratories
Faster and Stabler Wi-Fi
Slide 16
May 2013
- All LTE Handset Models are equipped with 5GHz Wi-Fi - 5GHz Wi-Fi APs are rolled out nationwide. More than 1.2M KDDI Home APs at Home. More than 0.2M KDDI Wi-Fi Spots in Public Areas.* (as of Sep. 2012)
* Some are not 5GHz compatible.
BandwidthCongestion/Interference Speed
2.4GHz Normally20MHz
Congested depending
on locationsHigh
5GHzTypically40MHz
Less Congested Very High
Submission
doc.: IEEE 11-13/0523r2
Katsuo Yunoki, KDDI R&D Laboratories
High Wi-Fi Usage at HomeKDDI Home AP
Slide 17
May 2013
- More than 1.2M installed
- Among Home AP Users, some 66% of data migrated to Wi-Fi at around 11pm (peak hour in residential area)
- This high usage rate was achieved by providing KDDI “Connection Manager App.”
KDDI Home AP Usage Status
Among Home AP users, some 66% ofdata migrated to Wi-Fi at around
11PM
66%Wi-Fi
KDDI Home AP
Submission
doc.: IEEE 11-13/0523r2May 2013
Katsuo Yunoki, KDDI R&D LaboratoriesSlide 18
“Connection Manager App.”
Pre-installed Easy Home AP setup
- For public Wi-Fi usage: No user setup for KDDI’s public
Wi-Fi No user operation Automatic connection control
(next Slide)
KDDI is providing Android App. for Wi-Fi easier start-up.
Submission
doc.: IEEE 11-13/0523r2May 2013
Katsuo Yunoki, KDDI R&D LaboratoriesSlide 19
Connect/Disconnect Control
“Connection Manager App.” controls timing of association and disconnection in order to avoid communication problem at Wi-Fi fringe area.Cellular BS
Fringe area
Keep Wi-Fi,difficult to communicate
APw
w
w/o
weak signal
w/o
??
: with CM App.
: without CM App.
OK!!
Connect with cellular
Submission
doc.: IEEE 11-13/0523r2May 2013
Katsuo Yunoki, KDDI R&D LaboratoriesSlide 20
EAP Authentication
- EAP-AKA + 802.1x have been implemented for user authenticationFor all LTE Android handsets.This USIM card based user authentication is
completed during link setup. So interruption time of user data communication is very short.
Previously, HTTP based user authentication was used for CDMA-only handsets. Interruption of user data communications is needed during this process. It requires some seconds to wait for.
Submission
doc.: IEEE 11-13/0523r2May 2013
Katsuo Yunoki, KDDI R&D LaboratoriesSlide 21
R&D Activity
- Link Aggregationis a function which communicates on Cellular and Wi-Fi link simultaneously. It may make Wi-Fi connectivity problems invisible. Because cellular communication will be maintained at that time period.
